RESUMO
Antibiotic resistance genes can easily be transferred between bacteria in the biofilm. In the dairy industry, many bacterial species forming biofilms on the surfaces of equipment are widely reported. The experiments reported in this research paper aimed to investigate the carbapenem resistance and biofilm formation properties of Enterobacterales isolates which are spoilage microorganisms obtained from raw milk. In addition, the study determined that whether there was a relationship between the biofilm formation ability or the protein spectra of these isolates. In this study, ninety-two Enterobacterales isolates collected from 173 raw milk samples were investigated. Initially, the isolates were identified as Citrobacter braakii (n = 18), Citrobacter freundii (n = 12), Enterobacter asburiae (n = 1), Enterobacter cloacae (n = 3), Escherichia coli (n = 10), Hafnia alvei (n = 18), Klebsiella oxytoca (n = 1), Serratia fonticola (n = 24), Serratia liquefaciens (n = 4), and Serratia marcescens (n = 1) using MALDI-TOF MS. As a result, carbapenem resistance was determined in 6.5% of the isolates by CIM test, MHT, and the disk diffusion methods, but none of them had blaOXA-48, blaKPC, blaNDM-1, blaOXA23, blaOXA-58, blaOXA-51, blaVIM, and blaIMP genes. This may be due to the effect of other resistance mechanisms such as porin loss or increased flow pump activity. Furthermore, biofilm formation (weak and moderate) was detected in 97.8% of the Enterobacterales isolates. The mass spectra of the moderate biofilm producer isolate of Serratia spp. and the mass spectra of the weak biofilm producers of E.coli presented similarities.
Assuntos
Enterobacteriaceae , Leite , Animais , Enterobacteriaceae/genética , Leite/metabolismo , beta-Lactamases/genética , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Escherichia coli/metabolismo , Carbapenêmicos/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana , Proteínas de Bactérias/genéticaRESUMO
BACKGROUND: The long-standing antimicrobial resistance (AMR) pandemic has proven difficult to resolve and is becoming more complex, especially in the context of increasing forced migration, with little evidence around patterns of AMR in migrant communities. This study aimed to determine the frequency in the carriage of common types of antimicrobial-resistant bacteria between Syrian refugees and the local communities in Türkiye: extended-spectrum ß-lactamase (ESBL), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). METHODS: We collected nasal swabs and stool samples from the study participants, the local community members, and refugees, between September 2020 and March 2021. We screened clinical samples for the presence of ESBL, MRSA and VRE. Antimicrobial-resistant bacterial isolates were tested by phenotypic analysis to determine the AMR status. RESULTS: The study included a total of 3960 participants: 1453 individuals in the local community (36.2%) and 2525 Syrian refugees (63.8%). Overall, a significantly greater proportion of refugees (6.7%) carried MRSA compared to the local community (3.2%) (P < 0.001). The ESBL-positivity rate was 17.9% in Syrian refugees and 14.3% in the local community (P = 0.041). Carbapenemase activity was detected in three isolates from Syrian refugees. No VRE was detected in Syrian refugees or the local community. CONCLUSIONS: This large, community-based study on the frequency and the distribution of AMR among Syrian refugees and the local population is the first study in Türkiye.
RESUMO
In this study, it was aimed to determine the possible factors affecting the clinical importance of Corynebacterium striatum isolates, which were accepted as infectious or contamination/colonization agents, by comparing their clinical and microbiological characteristics, antimicrobial susceptibility results, biofilm forming abilities and genotypic characteristics. The patients with C.striatum growth in the clinical samples sent to the laboratory were evaluated as infection or contamination/colonization with the evaluation of the examination findings and other laboratory parameters by the relevant physician. This study included 58 isolates, 29 of which were considered as infection and 29 as contamination/colonization. Length of hospital stay, presence of underlying disease [diabetes mellitus (DM), neurological disease, ischemic heart disease, chronic kidney disease, solid tumor], surgical operation status in the last month, and antibiotic use in the last three months of the patients were examined. Identification of the bacterial type was made with MALDI-TOF MS (Bruker/Germany) system. Antimicrobial susceptibility tests were performed by disc diffusion and gradient diffusion method and evaluated according to EUCAST standards. Biofilm production was determined in 96-well microtiter plates on negatively charged polystyrene surfaces. Clonal analyzes were performed by PFGE method using Xba1 enzyme. It was observed that there was no difference in terms of demographic characteristics in the two patient groups included in the study. It was observed that C.striatum strains isolated from outpatients were mostly found in the contamination/ colonization group. The presence of diabetes mellitus, ischemic heart disease, chronic kidney disease and solid tumor was not statistically different in the two patient groups. It was observed that C.striatum strains grown in the samples of patients with neurological disease were mostly found in the infectious agent group (p= 0.025). It has been observed that C.striatum strains grown purely in culture were mostly found in the infectious agent group (p= 0.001). Biofilm production was found to be significantly higher in the infectious agent group (p= 0.015). In antimicrobial susceptibility tests, it was observed that there was widespread multidrug resistance (MDR) in both groups and there was no significant difference between the groups in terms of antimicrobial susceptibility. In our study, it was determined that the strains showed very different PFGE patterns and were not clonally related to each other. In this study, it was determined that the demographic characteristics and comorbidities of the patients were not helpful in evaluating the clinical significance of C.striatum. Biofilm production was observed to be a common virulence factor in C.striatum strains. It was thought that there may be difficulties in the treatment of C.striatum in the future due to the widespread MDR detection among this bacterium strains. Our study contributes to draw attention to the increase in C.striatum infections, resistance and virulence factors.
Assuntos
Corynebacterium , Diabetes Mellitus , Humanos , Antibacterianos/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana MúltiplaRESUMO
BACKGROUND: In our study, we evaluated the in vitro activities of plazomicin, amikacin, gentamicin, and tobramycin among fifty carbapenem resistant Klebsiella pneumoniae (CR-Kp) isolates. Aminoglycoside resistance genes in selected CR-Kp strains were also examined. METHODS: Minimum inhibitory concentration (MIC) of meropenem, plazomicin, tobramycin, gentamicin, and amikacin were determined by gradient test (G-test) method. In all strains carbapenemase activity was assessed by polymerase chain reaction (PCR). Aminoglycoside modifying enzyme (AME) genes in 14 CR-Kp strains that are resistant to at least one of tobramycin, gentamicin, and amikacin among fifty CR-Kp isolates, and 16S ribosomal methylase genes in 6 CR-Kp strains with plazomicin MIC ≥ 128 mg/L were investigated by PCR method. RESULTS: The most frequently detected carbapenemase enzyme in the strains in our study was OXA-48 (88%). Aminoglycoside susceptibilities of all isolates were determined; plazomicin 84%, amikacin 66%, gentamicin 50%, tobramycin 18%. The most common AME gene positivities were found, 93% (n = 13) ant(3')-I, 78% (n = 11) aac(6')-Ib, 57% (n = 8) aac(3')-IV, 42% (n = 6) aac(3')-IIa, and 29% (n = 4) aph(3')-VI. Most of the isolates examined for the presence of AME carry at least two or more AME genes. The most common 16S ribosomal methylase gene was rmtH. In our study, MIC values of ≥ 256 µg/mL were found in 6 (12%) of 50 isolates against amikacin, tobramycin, and gentamicin, including plazomicin. At least two 16S ribosomal methylase gene positivity has been shown in these 6 strains. CONCLUSIONS: In our study, increased in vitro efficacy of plazomicin was shown in CR-Kp isolates comparing to other aminoglycosides. Plazomicin is an effective treatment option against CR-Kp isolates and needs to be sup-ported by clinical studies.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Klebsiella pneumoniae , Amicacina/farmacologia , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Gentamicinas/farmacologia , Humanos , Meropeném , Testes de Sensibilidade Microbiana , Sisomicina/análogos & derivados , Tobramicina/farmacologiaRESUMO
INTRODUCTION: Ralstonia insidiosa, a gram-negative waterborne bacteria able to survive and grow in any type of water source, can cause nosocomial infections, and are considered emerging pathogens of infectious diseases in hospital settings. In this study, we report an outbreak of R. insidiosa at our center related to contaminated heparinized syringes. MATERIAL AND METHODS: The present study was conducted in a tertiary care university hospital in Turkey. An outbreak analysis was performed between September 2021 and December 2021. Microbiological samples were obtained from environmental sources and from patient blood cultures. Species identification was performed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). To investigate the clonality of strains, all confirmed isolates were sent to the National Reference Laboratory and pulsed-field gel electrophoresis (PFGE) was used to perform molecular typing. RESULTS: Seventeen R. insidiosa isolates were identified from the blood cultures of 13 patients from various wards and intensive care units. Isolates from seven patient blood cultures and two heparinized blood gas syringes were characterized by PFGE. All isolates were found to belong to the same clone of R. insidiosa. CONCLUSION: R. insidiosa was identified as the cause of a nosocomial infection outbreak in our hospital, which was then rapidly controlled by the infection-control team. When rare waterborne microorganisms grow in blood or other body fluid cultures, clinicians and the infection-control team should be made aware of a possible outbreak.
Assuntos
Infecção Hospitalar , Sepse , Infecção Hospitalar/microbiologia , Surtos de Doenças , Humanos , Ralstonia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , SeringasRESUMO
In this study, it was aimed to determine the antibiotic resistance of Escherichia coli strains isolated from samples taken from various children's parks of Ankara and to confirm the resistance by molecular methods. Five hundred fifty-four samples, including soil samples from 140 different parks and 414 swab samples from slides, swings, ferris wheels, seesaws, and other toys from 176 different parks, were taken. Fourty E. coli strains isolated from these samples were included in the study. Antibiotic susceptibility tests of 40 E. coli isolates were performed by EUCAST recommendations. The resistance rates of E. coli isolates were found as ciprofloxacin 5%, ampicillin 17%, trimethoprim/sulfamethoxazole 15%, streptomycin 12.5%, tobramycin 5%, gentamicin 5%, cefotaxime 2.5%, and ceftazidime 2.5%. Intermediate rates were found as 95%, 90%, and 70% for tobramycin, gentamicin, and streptomycin respectively. blaCTX-M ß-lactamase gene was investigated for an isolate determined to be resistant to both cefotaxime and ceftazidime but blaCTXM gene could not be detected. Aminoglycoside resistance of strains has been investigated because of high intermediate sensitivity rates. For this purpose, aac(6')-Ib, aac(3')-IIa, aph(3')-VI, ant(3')-I, aac(3')-IV, ant(2')-Ia genes scanned, and were detected 97.5% of our isolates ant (3')-I, %25 aac(6')-Ib', 5% aac(3')-IIa, 2.5% ant(2')-Ia. Also, aph(3')-VI, and aac(3')-IV genes could not be detected in any of the isolates. Consequently, it has been revealed that resistant E. coli strains isolated from children's parks can pose a potential risk in public health for transmission of resistant genes.
Assuntos
Farmacorresistência Bacteriana , Escherichia coli , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Criança , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , beta-Lactamases/genéticaRESUMO
Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are a growing concern for public health resulting in increase in morbidity, length of hospital stay, and cost of treatment. MRSA nasal swab screening may give clinicians additional information for decision of empiric antimicrobial agents. While increasing antibiotic resistance leads to new treatment approaches, bacteriophages are one of the most promising methods for these alternatives. It was aimed to determine the effectiveness of bacteriophages against MRSA isolates. Nasal swab samples were collected from outpatients without any evidence of infection who applied to Hatay, Mersin and Gaziantep family and immigration health centers. A series (35) were isolated from Turkish patients, and G series (64) were isolated from Syrian immigrants. Methicillin resistance was determined phenotypically and genotypically. Also, antibiotic susceptibilities of all isolates were determined against erythromycin, clindamycin, gentamicin, linezolid, rifampicin, and mupirocin. The total antimicrobial resistance rates of isolates were found to be 11%, 28%, 8%, 5%, 16%, 19%, and 29% respectively. The high susceptibility rate against ciprofloxacin (88.8%) was remarkable. The overall susceptibility of MRSA strains to ENKO, INTESTI, PYO, SES, and staphylococcal bacteriophages was 67.7%, 55.5%, 53.5%, 61.6% and 44.4%, respectively. The antibiotic susceptibility rates (except erythromycin) and efficacy of bacteriophages were higher in group A. Considering that high efficacy rates were not achieved in the study and the sensitivity rates of Turkish isolates to all phages were found to be higher than those of Syrian isolates, searching for phages in the geographic regions where the pathogen is common may be helpful to obtain suitable phages for treatment.
Assuntos
Bacteriófagos , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriófagos/genética , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureusRESUMO
The selection of therapeutic agent to be used for the treatment of multidrug-resistant bacteria is a major concern. Polymyxin B use has been commenced in Turkey, although its clinical breakpoint is not listed in the EUCAST. This study aimed to determine the correlation between the MIC values of polymyxin B and colistin. A total of 505 isolates, including 122 isolates of Escherichia coli and 383 isolates of Klebsiella pneumoniae were included in the present study. All the isolates were assessed for colistin and polymyxin B using the broth microdilution method. The categorical agreement in the E. coli isolates was 98.4%, and the rate of very major error was 33.3%. The categorical agreement in the K. pneumoniae isolates was 99.5%, the rate of major error was 0.36%, and the rate of very major error was 0.98%. In the evaluation of the essential agreement, 1.6% error in E. coli and 2.3% error in K. pneumoniae were observed. It was concluded that polymyxin B should never be used in the treatment of the isolates reported as colistin-resistant, and if the MIC values are above 4 mg/L in E. coli and K. pneumoniae. Our results indicate importance of reporting both polymyxin B and colistin susceptibility results of clinical isolates.
RESUMO
Antibiotic resistance is one of the most important public health problem and one of the most critical steps in preventing resistance is the monitorization of the resistance. Local, regional and global monitoring enables the spread of antibiotic resistance to be understood more clearly. In this study, it was aimed to evaluate the results of the pilot study for the establishment of molecular-based carbapenem surveillance system in Escherichia coli and Klebsiella pneumoniae isolates and to investigate the carbapenemase epidemiology in Turkey. Hospitals (n= 28) from 26 different statistical level II regions from Turkey were included in the study. The hospitals participated in the study submitted ten carbapenem susceptible and ten carbapenem resistant E.coli and K.pneumoniae isolates to our laboratory that were isolated in two different periiods of six-month either between 1 March-31 August or 1 April-30 September 2019. A total of 509 isolates were collected from 26 of the 28 participating hospitals in the study. Isolates were identified by matrix assisted laser desorptionization-time of flight mass spectrophotometry (MALDI TOF MS) (Bruker Daltonics, Germany) method and antibiotic susceptibility tests for imipenem, meropenem and colistin were studied by broth microdilution. Moreover, susceptibilities to amikacin, amoxicillin-clavulanic acid, ampicillin, aztreonam, cefepime, cefotaxime, ceftazidime, ciprofloxacin, ertapenem, gentamicin, piperacillin-tazobactam, tobramycin and trimethoprim-sulfamethoxazole were determined by disc diffusion method. The resistance genes were investigated in isolates which were found to be phenotypically resistant to carbapenem and colistin, in house method was used to investigate carbapenemase genes and a commercial colistin resistant real-time PCR kit (Biospeedy, Turkey) was used for colistin resistance genes. In total, 493 of the 509 isolates collected from hospitals were identified as E.coli (25.7%, n= 127) and K.pneumoniae (74.3%, n= 366) and included in the study. It was determined that 31% of the isolates evaluated were from community-acquired infections and 69% were either from healthcare-associated infections or from colonization sites. Among the tested isolates, 248 (50.3%) were susceptible to carbapenems and 245 (49.7%) were resistant. The types of carbapenemases in carbapenemase-producing were OXA-48 (52.2%), KPC (16.1%), NDM-1 (15%), OXA-48 + NDM-1 (12.6%), KPC + NDM-1 (2.8%) and VIM (0.5%) and OXA-48+VIM (0.5%). Resistance to colistin was detected in 23.3% of the isolates but mcr1-8 genes were not detected. It was found that all colistin resistant isolates are resistant to at least one of the carbapenems. The importance of a molecular-based antimicrobial resistance surveillance system in our country was demonstrated with this pilot study. It is thought that continuous monitoring of these epidemiological features will contribute to the management of infections due to carbapenemase-producing organisms.
Assuntos
Proteínas de Bactérias , Infecções por Klebsiella , Klebsiella pneumoniae , beta-Lactamases , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Humanos , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , Projetos Piloto , Turquia/epidemiologia , beta-Lactamases/genéticaRESUMO
Francisella tularensis is a gram-negative, coccobasillus, facultative intracellular bacteria and causes a zoonotic disease, tularemia in humans. F.tularensis has four subspecies, which have different virulences for humans as F.tularensis subsp. tularensis, F.tularensis subsp. holarctica, F.tularensis subsp. mediasiatica and F.tularensis subsp. novicida. F.tularensis subsp. tularensis is the most virulent subspecies and mortality rate is high in human cases. F.tularensis subsp. holarctica, which has been reported in our country to date, has lower virulence than that of subsp. tularensis, and causes rare lethality among untreated patients. According to the erythromycin resistance and the properties of glucose-glycerol fermentation, F.tularensis subsp. holarctica has three biovar as biovar I, biovar II and biovar japonica. F.tularensis subsp. mediasiatica has been reported only in a few central asian countries and its virulence is similar to the F.tularensis subsp. holarctica F.tularensis subsp. novicida is avirulent for immunocompetent individuals but has been observed to cause infection in immunocompromised individuals. The aim of this study was to determine the F.tularensis subspecies in 259 F.tularensis strains isolated from clinical specimens, drinking water and a rodent sample and 517 F.tularensis PCR-positive DNA isolated from clinical specimens between years 2009 and 2014. Conventional PCR was performed using primers specific for the RD1 (Region Difference) region of F.tularensis. Subspecies were differentiated depending on the difference in PCR amplification product size. In our study, F.tularensis subsp. holarctica was detected in 764 samples yielding 922 base pair (bp) amplification product. The DNA samples obtained from one water and 11 lymph aspirates were determined as F.tularensis subsp. holarctica biovar japonica. The DNA sequence analysis of the amplification product of the RD1 region of the isolate from water sample was determined. The 1136 bp nucleotide sequence obtained from the DNA sequence analysis was 100% similar to F.tularensis subsp. holarctica biovar japonica (FCS075 strain-accesion number AF469618) when compared with GenBank data. The whole genome sequence of this isolate was also determined and recorded to GenBank with accesion number CP007148. None of the samples used in our study belonged to other sub-species. F.tularensis subsp. holarctica biovar japonica positive 11 lymph aspirate samples were sent to our center from Ankara (n= 1), Kayseri (n= 1) and Afyon (n= 9) provinces. The results of the current study revealed that F.tularensis subsp. holarctica biovar japonica caused a tularemia outbreak in a village in Afyon province at first time and it was observed sporadically in two other different provinces.
Assuntos
Francisella tularensis , Tipagem Molecular , Tularemia , Animais , DNA Bacteriano/genética , Francisella tularensis/classificação , Francisella tularensis/genética , Francisella tularensis/patogenicidade , Humanos , Tularemia/microbiologia , Turquia , Virulência , Zoonoses/microbiologiaRESUMO
Influenza A(H1N1)pdm09 pandemic virus causing the 2009 global outbreak moved into the post-pandemic period, but its variants continued to be the prevailing subtype in the 2015-2016 influenza season in Europe and Asia. To determine the molecular characteristics of influenza A(H1N1)pdm09 isolates circulating during the 2015-2016 season in Turkey, we identified mutations in the hemagglutinin (HA) genes and investigated the presence of H275Y alteration in the neuraminidase genes in the randomly selected isolates. The comparison of the HA nucleotide sequences revealed a very high homology (>99.5%) among the studied influenza A(H1N1)pdm09 isolates, while a relatively low homology (96.6%-97.2%), was observed between Turkish isolates and the A/California/07/2009 vaccine virus. Overall 14 common mutations were detected in HA sequences of all 2015-2016 influenza A(H1N1)pdm09 isolates with respect to the A/California/07/2009 virus, four of which located in three different antigenic sites. Eleven rare mutations in 12 HA sequences were also detected. Phylogenetic analysis revealed that all characterized influenza A(H1N1)pdm09 isolates formed a single genetic cluster, belonging to the genetic subclade 6B.1, defined by HA amino acid substitutions S84N, S162N, and I216T. Furthermore, all isolates showed an oseltamivir-sensitive genotype, suggesting that Tamiflu (Oseltamivir) could still be the drug of choice in Turkey.
Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Mutação , Substituição de Aminoácidos , Antivirais/farmacologia , Farmacorresistência Viral/genética , Variação Genética , Genótipo , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/epidemiologia , Oseltamivir/farmacologia , Filogenia , Turquia/epidemiologiaRESUMO
Human rotavirus A (RVA) is the main etiological agent of watery diarrhea among children under 5 years of age worldwide. The aims of this study were to investigate the prevalence and diversity of RVA genotypes circulating in Turkey during a 2-year sentinel surveillance study. A total of 1639 rotavirus antigen-positive stool samples were obtained from children younger than 5 years of age hospitalized with acute gastroenteritis. Rotavirus G and P genotypes were determined by reverse transcription polymerase chain reaction (RT-PCR) with consensus primers for the VP7 and VP4 genes, followed by semi-nested type-specific multiplex PCR. Rotavirus RNA was detected in 1396 (85.3%) of the samples tested. The highest detection rate (38.2%) was obtained among children in the 0-12 months age group, followed by children in the 13-24 months age group (36.2%). The most prevalent genotype was G1P[8] (24.6%) followed by G3P[8] (19.6%), G9P[8] (12.2%), G2P[4] (9.5%), G2P[8] (6.5%), and G4P[8] (4.8%). The proportions of uncommon and mixed genotypes were 21.5% and 1.14%, respectively. The large number of genotypes observed, including common, uncommon, and mixed types, indicates a high heterogeneity of RVA strains circulating in Turkey. The current study also exhibited dramatic fluctuations on the prevalences of the common genotypes, with increases in G3 and G1 and decreases in G9 and G2 from 2014-2016.
Assuntos
Variação Genética , Genótipo , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/classificação , Rotavirus/genética , Pré-Escolar , Fezes/virologia , Feminino , Técnicas de Genotipagem , Humanos , Lactente , Recém-Nascido , Masculino , Epidemiologia Molecular , Prevalência , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/isolamento & purificação , Vigilância de Evento Sentinela , Turquia/epidemiologiaRESUMO
Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type B are responsible for about 80-85% of acute bacterial meningitis cases among adults and in our country it is mandatory to report bacterial meningitis cases caused by these agents. In recent years, disease control programs have focused especially on these three pathogens in our country. It is very important to know the causative agent of meningitis for prevention/control measures, choice of treatment regimen, and prediction of the severity and the course of the disease. Rapid diagnosis of meningococcal meningitis is especially vital. In addition, the identification of N.meningitidis serogroups in the community is also important for the decision of the type and combination of vaccine to be administered. The aim of this study was to optimize the real-time multiplex polymerase chain reaction (Rt-multiplex PCR) for the diagnosis of the disease and serogrouping of N.meningitidis in clinical samples in a direct, quick and reliable way. In this study, three Rt-multiplex PCR assays were optimized and standardized for the detection of N.meningitidis, H.influenzae and S.pneumoniae (NHS mix) and for the serogrouping of N.meningitidis (BCY mix and AWX mix) in our laboratory. Sensitivity of the Rt-multiplex PCR method was detected by reference strains and simulation studies. Forty three samples (41 cerebrospinal fluid (CSF), 1 serum and 1 clinical isolate) with the suspicion of acute bacterial meningitis and six nasopharyngeal isolates sent to National Reference Laboratory for Molecular Microbiology between July 2012-May 2014 were included in the present study. All samples were examined with the Rt-multiplex PCR methods. Clinical isolates were studied by both conventional and Rt-multiplex PCR methods. Oxidase, catalase test, Gram stain, API-NH and agglutination tests with specific antisera were performed in the National Respiratory Pathogens Reference Laboratory. The detection limit of the method, which was optimized and standardized in our laboratory was determined as 102 cfu/ml. The CT (threshold cycle) value in this dilution was detected approximately as 35. N.meningitidis was detected in 14 of the 41 CSF samples by the NHS mix. However, only 10 of the positive samples could be typed with BCY mix and AWX mix. Eight (80%) of them were serogroup B, one of each was (10%) serogroup A and serogroup W135, respectively. All the isolates (six nasopharyngeal and one clinical specimen) were identified as N.meningitidis serogroup B by Rt-multiplex PCR and the isolates were also confirmed by conventional methods. The CSF specimens with CT value > 35 could not be typed. We concluded that the Rt-multiplex PCR method is a rapid and reliable test for the direct diagnosis of acute bacterial meningitis due to NHS and serogrouping of N.meningitidis. Rapid diagnosis plays an important role for the treatment and control of the disease, and serogrouping of the agent plays an important role in terms of prevention/control and vaccination policies.
Assuntos
Meningites Bacterianas , Reação em Cadeia da Polimerase Multiplex , Neisseria meningitidis , Humanos , Meningites Bacterianas/diagnóstico , Neisseria meningitidis/classificação , Neisseria meningitidis/genética , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Francisella tularensis DNA extractions and isolates from the environment and humans were genetically characterized to elucidate environmental sources that cause human tularemia in Turkey. Extensive genetic diversity consistent with genotypes from human outbreaks was identified in environmental samples and confirmed water as a source of human tularemia in Turkey.
Assuntos
Francisella tularensis/patogenicidade , Tularemia/epidemiologia , Doenças Transmitidas pela Água/epidemiologia , Animais , Surtos de Doenças , Genótipo , Humanos , Filogeografia/métodos , Roedores , Turquia/epidemiologia , Água , Doenças Transmitidas pela Água/genéticaRESUMO
BACKGROUND: Stenotrophomonas maltophilia is a gram-negative bacterium that can cause hospital infections and outbreaks within hospitals. This study aimed to evaluate an outbreak of Stenotrophomonas maltophilia, caused by ready-to-use commercial syringes containing liquid lithium and heparin for arterial blood gas collection in a university hospital. METHODS: Upon detecting an increase in Stenotrophomonas maltophilia growth in blood cultures between 15.09.2021 and 19.11.2021, an outbreak analysis and a case-control study (52 patients for the case group, 56 patients for the control group) were performed considering risk factors for bacteremia. Samples from possible foci for bacteremia were also cultured. Growing bacteria were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The genetic linkage and clonal relationship isolates were investigated with pulsed-field gel electrophoresis (PFGE) in the reference laboratory. RESULTS: In the case-control study, the odds ratio for the central venous catheter [3.38 (95% confidence interval [CI]: 1.444, 8.705 ; p = 0.006)], for surgery [3.387 (95% confidence interval [CI]: 1.370, 8.373 ; p = 0.008)] and for arterial blood gas collection history [18.584 (95% confidence interval [CI]:4.086, 84.197; p < 0.001)] were identified as significant risk factors. Stenotrophomonas maltophilia growth was found in ready-to-use commercial syringes used for arterial blood gas collection. Molecular analysis showed that the growths in the samples taken from commercial syringes and the growths from blood cultures were the same. It was decided that the epidemic occurred because the method for sterilization of heparinized liquid preparations were not suitable. After discontinuing the use of the kits with this lot number, the outbreak was brought under control. CONCLUSIONS: According to our results, disposable or sterile medical equipment should be included as a risk factor in outbreak analyses. The method by which injectors containing liquids, such as heparin, are sterilized should be reviewed. Our study also revealed the importance of the cooperation of the infection control team with the microbiology laboratory.
Assuntos
Infecção Hospitalar , Surtos de Doenças , Infecções por Bactérias Gram-Negativas , Stenotrophomonas maltophilia , Stenotrophomonas maltophilia/isolamento & purificação , Humanos , Estudos de Casos e Controles , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Masculino , Feminino , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Pessoa de Meia-Idade , Idoso , Adulto , Fatores de Risco , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Hospitais Universitários , Seringas/microbiologia , Eletroforese em Gel de Campo Pulsado , Idoso de 80 Anos ou mais , Heparina/farmacologiaRESUMO
Genetic characterization of measles viruses (MVs) combined with acquisition of epidemiologic information is essential for measles surveillance programs used in determining transmission pathways. This study describes the molecular characterization of 26 MV strains (3 from 2010, 23 from 2011) obtained from urine or throat swabs harvested from patients in Turkey. MV RNA samples (n = 26) were subjected to sequence analysis of 450 nucleotides comprising the most variable C-terminal region of the nucleoprotein (N) gene. Phylogenetic analysis revealed 20 strains from 2011 belonged to genotype D9, 3 to D4, 2 strains from 2010 to genotype D4 and 1 to genotype B3. This study represents the first report describing the involvement of MV genotype D9 in an outbreak in Turkey. The sequence of the majority of genotype D9 strains was identical to those identified in Russia, Malaysia, Japan, and the UK. Despite lack of sufficient epidemiologic information, the presence of variants observed following phylogenetic analysis suggested that exposure to genotype D9 might have occurred due to importation more than once. Phylogenetic analysis of five genotype D4 strains revealed the presence of four variants. Epidemiological information and phylogenetic analysis suggested that three genotype D4 strains and one genotype B3 strain were associated with importation. This study suggests the presence of pockets of unimmunized individuals making Turkey susceptible to outbreaks. Continuing molecular surveillance of measles strains in Turkey is essential as a means of acquiring epidemiologic information to define viral transmission patterns and determine the effectiveness of measles vaccination programs designed to eliminate this virus.
Assuntos
Surtos de Doenças , Vírus do Sarampo/genética , Sarampo/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genoma Viral , Genótipo , História do Século XXI , Humanos , Lactente , Masculino , Sarampo/história , Vírus do Sarampo/classificação , Dados de Sequência Molecular , Filogenia , RNA Viral/sangue , RNA Viral/genética , RNA Viral/urina , Turquia/epidemiologia , Adulto JovemRESUMO
Determination of the distribution of rotavirus genotypes is essential for understanding the epidemiology of this virus responsible for nearly half a million of deaths in patients with gastroenteritis worldwide. In the present study, we aimed to genotype the rotavirus strains isolated from diarrheal stool samples in children under 5 years old. A total of 1297 fecal samples were collected, and rotavirus antigen was detected in 73 of these samples. Antigen-positive samples were transferred to the Public Health Agency of Turkey, Molecular Microbiology Research Laboratory, and were tested for determination of genotypes G and P using semi-nested multiplex polymerase chain reaction method performed with consensus- and genotype-specific primers. Twelve specimens were found to be negative for rotavirus in genotyping method. All the positive-strains were in G1-4, G8-9, P(4), P(8), and P(9) genotypes. The most frequent GP genotype combinations were found to be G9P(8) in 21 strains (34.4%), G2P(4) in 14 strains (23.0%), and G1P(8) in 12 strains (19.7%). We found 10 distinct genotypes amongst a total of 61 strains. Among the strains isolated and genotyped in our study, 90.2% (55/61) and 67.2% (41/61) have already been included in the two existing commercial vaccines. In conclusion, these findings implicate the necessity of development of region-specific vaccines after evaluation of the local genotype distribution. Further studies on the large number of rotavirus strains would contribute to this process.
Assuntos
Gastroenterite/virologia , Genótipo , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/isolamento & purificação , Pré-Escolar , Feminino , Gastroenterite/epidemiologia , Humanos , Masculino , Prevalência , Estudos Retrospectivos , Rotavirus/genética , TurquiaRESUMO
BACKGROUND: Group A rotaviruses are the most common causative agent of acute gastroenteritis among children less than 5 years of age throughout the world. This sentinel surveillance study was aimed to obtain baseline data on the rotavirus G and P genotypes across Turkey before the introduction of a universal rotavirus vaccination program. METHODS: Rotavirus antigen-positive samples were collected from 2102 children less than 5 years of age who attended hospitals participating in the Turkish Rotavirus Surveillance Network. Rotavirus antigen was detected in the laboratories of participating hospitals by commercial serological tests such as latex agglutination, immunochromatographic test or enzyme immunoassay. Rotavirus G and P genotypes were determined by reverse transcription polymerase chain reaction (RT-PCR) using consensus primers detecting the VP7 and VP4 genes, followed by semi-nested type-specific multiplex PCR. RESULTS: RT-PCR found rotavirus RNA in 1644 (78.2%) of the samples tested. The highest rate of rotavirus positivity (38.7%) was observed among children in the 13 to 24 month age group, followed by children in the age group of 25 to 36 months (28.3%). A total of eight different G types, six different P types, and 42 different G-P combinations were obtained. Four common G types (G1, G2, G3, and G9) and two common P types (P[8] and P[4]) accounted for 95.1% and 98.8% of the strains, respectively. G9P[8] was the most common G/P combination found in 40.5% of the strains followed by G1P[8] (21.6%), G2P[8] (9.3%), G2P[4] (6.5%), G3P[8] (3.5%), and finally, G4P[8] (3.4%). These six common genotypes included 83.7% of the strains tested in this study. The rate of uncommon genotypes was 14%. CONCLUSION: The majority of the strains analyzed belonged to the G1-G4 and G9 genotypes, suggesting high coverage of current rotavirus vaccines. This study also demonstrates a dramatic increase in G9 genotype across the country.
Assuntos
Antígenos Virais/genética , Proteínas do Capsídeo/genética , Vigilância em Saúde Pública , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/imunologia , Rotavirus/genética , Pré-Escolar , Genótipo , Humanos , Lactente , Prevalência , RNA Viral/análise , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/administração & dosagem , Análise de Sequência de RNA , TurquiaRESUMO
The serotonin (5-hydroxytryptamine) transporter (5HTt) gene has been reported to be associated with suicidal behavior. In this study, we have investigated the 5' promoter region (i.e., 5HTt gene-linked polymorphic region [5-HTTLPR]) and a 17-base pair variable number of tandem repeats polymorphism in the 5HTt gene for potential association with suicidal behavior in a Turkish population. Genotypes were determined for 182 subjects of suicide (86 attempted suicide and 96 completed suicide) and 181 healthy control subjects. Our results showed that allele frequencies at individual loci were not significantly different in the two groups. This absence of altered individual locus haplotype (allele) frequency suggests the lack of a significant genetic contribution by the 5-HTTLPR or variable number of tandem repeats variations to the expression of suicidal tendencies. However, our linkage disequilibrium analyses indicated that there may be a greater risk for suicidal behavior in carriers of the S10 and L12 alleles of 5-HTTLPR.
Assuntos
Íntrons , Polimorfismo Genético , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Suicídio , Sequências de Repetição em Tandem , Adulto , Feminino , Humanos , Masculino , TurquiaRESUMO
The aim of this study was to examine the effect of both promoter and intron polymorphisms of the serotonin transporter (5HTT) gene on posttraumatic stress disorder (PTSD) development. For this purpose, two polymorphisms of the 5-HTT gene, which are found in the promoter (5-HTT gene-linked polymorphic region) and second intron (variable number of tandem repeats) of the gene, were analyzed in 100 patients who were admitted to the Emergency Department after a mild physical trauma. None of the 5-HTT polymorphisms studied have an effect on PTSD development after a mild physical injury, but having L allele for 5-HTT gene-linked polymorphic region may cause milder hyperarousal symptoms in those patients who have developed PTSD.